They made several low value transactions at the electrical retailer Best Buy

The revelations will ramp up the pressure on the supermarket’s banking division, whose reputation has been damaged by the raid.

Cyber-security experts said Tesco should have acted more quickly to stop the flood of payments to overseas stores. The thieves loaded up on cheap goods to get around limits on mobile phone transactions.

“It didn’t feel as if Tesco Bank had much of a contingency plan in place,” said Dave Palmer of cyber-security firm Darktrace.